The answer is D.
f(x) = 3/x
g(x) = 3x
(g * f)(-9) = 3(3/-9)
(g * f)(-9) = 3(-1/3)
(g * f)(-9) = -1
The highlighted sector is exactly 3/4 of the circle area, because
is 3/4 of
which is a complete rotation.
Since you are given the radius, you can compute the area as

So, 3/4 of this area would be
squared cm.
The remaining sector, of course, is
squared cm.

192π is about 603.19 cm³.
well, it means if you grab a hmmmm cube, say that is 1cm x 1cm x 1cm, namely a 1cm tall, 1cm wide and 1cm long, whose value is 1cm³, you can fit 603.19 of those in that cylinder.